code: def calc_error_bar(df, column_name):
      """Adds error plus and minus for plotting"""
      error_plus = df[column_name + " Q3"] - df[column_name]
      error_minus = df[column_name] - df[column_name + " Q1"]
      df[column_name + " error plus"] = error_plus
      df[column_name + " error minus"] = error_minus
      return df
  
file_path: CrypTen/benchmarks/dash_app/load_data.py
imports: import os
  import pandas
label_desc: Use image node_id 8 for calling a global function with example usage: calc_error_bar(df, column_name) and returns: df